PFFF
Pressure front wall — squared bipolar shockwave
FFFF
Gas blowout — gated noise following the pressure front
BLAST
Friedlander muzzle pressure wave
CRACK
N-wave ballistic shockwave
SUPERSONIC
POP2
v6 projectile release pop — bipolar gas burst
CRACK2
v6 N-wave spike + swept LP noise burst
WHOOSH
Gas exit turbulence — muzzle "SHHH"
WOOSH2
v6 projectile air displacement — pass-by whoosh
SIZZLE2
v6 HP noise burst — high fire hiss
AIR
Negative phase backflow — smooth turbulent "fft"
LFE
Bipolar Friedlander sub-pulse — positive + rarefaction
SUB
Friedlander slow-decay — bipolar LP (DC-blocked)
SUB2
v6 freq-sweep sine chest punch
BODY
Impulse-excited chamber resonance + Brownian noise
TINK
Firing pin strike — inharmonic modal synthesis
SHHK
BCG rail scrape — resonant modes + stick-slip friction
CHUK
Casing pop — gas release + ejection scrape
SHING
Casing ejection — clattery multi-impact metallic burst
MECH2
v6 bolt carrier recoil — impact + scrape + spring
RECV
Receiver body resonance — steel housing modal ring
BSLAP
Buffer tube slam — bolt rear impact thud
RATTLE
Action rattle — loose parts clatter from bolt travel
REFL
Ground reflection — Maher 2007
ROOM
Early reflections — confined space pressure slam
TAIL
Distant acoustic decay — dry shot excited IR (shot-forge v6)
MIC
Mic saturation — Hacihabiboglu 2017